The mention of Jack Wilshere and bone bruising in the same sentence is generally sufficient to induce palpitations among the Arsenal support and so Arsène Wenger's reaction to the midfielder's latest scan results was not surprising. Rest, he said, was essential in order to prevent the problem in the left foot from escalating in the same destructive fashion as it had previously in the right.

The related conspiracy theory, however, reinforced the question that tracked Wenger to Munich on Tuesday, ahead of the Champions League last-16 second-leg tie against Bayern, which has been billed as Mission Impossible. Arsenal trail 3-1 from the first leg and no team in Champions League history have recovered from such a deficit away from home.

Arsenal have not played since the derby defeat at Tottenham Hotspur on 3 March and Wilshere, according to Wenger, should be fit to return against Reading at the Emirates on 30 March. He will sit out Saturday's visit to Swansea City, which is a blow, together with England's World Cup qualifiers against San Marino and Montenegro, which is less of a blow to Arsenal but, in what is very close to being a full month, the Swansea game stands to be the only one the midfielder will miss for his club in the Premier League.

It is no great leap to imagine Wenger considering this to be a good time for his star player to have a reviving rest before the final push for Champions League qualification via the league and, at the same time, it begs the question as to how seriously he will take the game at the Allianz Arena, which might have been one of the biggest of his career only for the events of the first leg to remove its lustre.

We will know only when the team-sheets drop but Bacary Sagna and Lukas Podolski have not travelled, because of niggling injuries, and neither has Wojciech Szczesny, the goalkeeper, who has been granted a "breather" in the wake of his erratic recent form and nervousness. Lukasz Fabianski, who is fit after ankle ligament damage, is primed to replace him and stake a claim for the Swansea game.

Moreover, Wenger is understood to be considering further changes, involving players who have not featured prominently in recent weeks. Laurent Koscielny is expected to start in central defence while Francis Coquelin, Aaron Ramsey, Tomas Rosicky and Alex Oxlade-Chamberlain have chances across the midfield. Santi Cazorla and Theo Walcott are in need of breaks. The fit-again Kieran Gibbs stands to play his first football since 30 January and Abou Diaby is back in the squad, despite Wenger describing him as a "bit short" after calf trouble.

Would Wilshere have played if Arsenal had been ahead from the first leg, or the tie more finely balanced? Would Wenger have considered any experimentation? There is the sense that Swansea is bigger than Bayern, which is born of cold reality but also sums up the downturn in Arsenal's fortunes.

The Szczesny situation has intriguing undercurrents, which run deeper than his need for a psychological break. Wenger has had cause to worry about the Pole's uber-confidence leading to questions related to his attitude and the manager has been repeatedly linked with the signing of a new goalkeeper. He is rarely even vaguely critical of his players in public and, as such, his candour about Szczesny had a worrying feel.

"He has played many games, and under a lot of pressure, and recently he had one or two games where he was performing less," Wenger said. "With goalkeepers, it's always a difficult problem. Do you keep them in to find the confidence back or do you give them a breather? I decided to give him a breather, just to refresh him and not [for him] to be under increasing pressure. Because once people start to speak about you, you think, 'Now I cannot afford anything', and that's where you make the mistakes."

Wenger dug deep to supply the evidence as to why Arsenal could shock Bayern. He noted how his team had won away against all of the major European clubs, apart from Barcelona (he forgot to mention Bayern, too), and he talked up the achievement of 2005-06, when they reached the final without conceding a goal in the knockout phase.

Yet the manager could not rouse himself to thump the tub with real gusto. It might have sounded incongruous. Bayern's record home defeat in Europe is 2-0, which would not be enough for Arsenal, but the reasons why the German team have been cast as certainties are more than merely historical. Bayern have carried all before them this season, even if they refuse to get carried away.

"I have no interest in dividing up the skin before I kill the bear," said the Bayern manager, Juup Heynckes. "My team is not listening to those saying we are the best team in Europe."